A new ad running in the special election for South Carolina's 1st district hits former governor Mark Sanford right in the Appalachian trail.

The Democratic super PAC House Majority PAC is behind the ad, the first in the race to directly attack the Republican candidate for his infidelity.

"I used to be for Mark Sanford, but not anymore," a female narrator says. "He skipped town to be with his mistress on Father's Day. Sanford even asked his wife for permission to have the affair, and wasted his taxpayer dollars on himself ... I was mortified, angry, embarrassed, betrayed."

The ad, part of a six-figure buy, comes the morning after Democrat Elizabeth Colbert Busch made a subtle reference to Sanford's 2009 disappearance to Argentina in the race's only debate.

“When we talk about fiscal spending and we talk about protecting the taxpayers, it doesn’t mean you take that money we saved and leave the country for a personal purpose,” Colbert Busch said.

Sanford replied that he "couldn’t hear what she said.”

South Carolina officials concluded in 2009 that Sanford did not use state funds for personal trips to New York and Argentina. He reimbursed the state $3,304 for part of an official state-sponsored trip to Brazil and Argentina during which he spent time with his mistress. A year later, Sanford paid $74,000 in fines to resolve ethics charges related to his travel and campaign spending.